At first glance the mound is nothing remarkable—just a pile of dirt and stone covered in trees and vegetation. It’s in the Guatemalan forest on the outskirts of the Classic Maya site of Xultún, near another site I’ve been studying for the past decade. At some point, looters dug a hole into it, looking for a tomb. I told the student who found an eroded wall with faint glimpses of paint, “There used to be something here, but there’s nothing now.” Still, I was curious. So I excavated to the back wall, and I saw a beautiful portrait of a king. There he was in Technicolor, with blue feathers. I laughed. I mean, what are the chances?

It’s rare to find ancient Maya murals, but I’ve had great luck over the years. I’d love for it to be due to some brilliance of mine, but it’s just luck. I can’t explain it. When we excavated the six-foot-wide room in this mound, we found paintings of several figures with the king. One is identified in glyphs as Younger Brother Obsidian. He’s holding a stylus. An entire wall is covered in mathematical calculations.

My hunch is that this may have been a workspace or teaching space for scribes, artists, or scholars. They were working things out for later public consumption. This room gives us a rare glimpse of Maya thought processes. When my colleagues and I studied four columns of huge numbers, we realized these were calculations based on the Maya calendar and astronomy that projected 2.5 million days—some 7,000 years—into the future.

This was done in A.D. 813 or 814, 75 years before Xultún’s final days. A lot of the Maya lowlands had already fallen silent. The collapse had begun. Trade routes and hubs of communication were all changing. At Xultún, folks were going about business as usual, but there was an undercurrent of anxiety. They wanted to tie events in their king’s life to larger cosmic cycles. They wanted to show that the king would be OK.

It’s important to understand that the ancient Maya predicted the world would continue. That was their point. They didn’t predict the end of the world. There would be cycles, new beginnings—but never endings. That’s what’s going on in this room. The numbers on the walls are calculations of when the same cosmic events would happen in the future. The Maya were looking for a guarantee that nothing would change. We keep looking for endings. It’s an entirely different mind-set. I would never have identified this nondescript mound as special. But this discovery implies that special things are everywhere. —William Saturno